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Published 2013-10-25 · Federal Register document 2013-24937

Airworthiness Directives; AgustaWestland S.p.A. (Agusta) Helicopters

Publication summary

We are adopting a new airworthiness directive (AD) for Agusta Model A109A, A109A II, A109C, A109E, A109K2, A109S, AW109SP, A119, and AW119 MKII helicopters. The emergency AD was sent previously to all known U.S. owners and operators of these helicopters. This AD requires, before further flight, inspecting certain Thomas coupling nuts on the tail rotor drive shaft line for a crack and replacing all the nuts if any nut is cracked. Also this AD requires replacing all affected Thomas coupling nuts within 10 hours time-in-service (TIS) or 30 days, whichever occurs first. This AD was prompted by two incidents of cracking on the nuts that connect the flexible disc coupling (Thomas coupling) with the splined adapter on the tail rotor drive shaft. We are issuing this AD to correct the unsafe condition on these helicopters.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:23:42.577882+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2013-a7b684f4a1b4614e
Source row
results[327]
Raw source SHA-256
a7b684f4a1b4614eef5ec9064d04a70a4701b45b0acd50058e29f235c625e705

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2013-20-51
Effective date printed in this edition
Unknown

Some source clauses remain unstructured. Read the complete publication for conditions that have not been interpreted here.

Read 8 complete recorded clauses
Applicability wording · Applicability
(a) Applicability

    This AD applies to the following Agusta S.p.A. (Type certificate 
currently held by AgustaWestland S.p.A) (Agusta) helicopters, with a 
tail rotor drive shaft flexible disc coupling (Thomas coupling) nut, 
part number (P/N) MS21042L4, certificated in any category:
    (i) Model A109A, A109A II, A109C, A109E, A109S, A109K2, AW109SP 
helicopters; and
    (ii) Model A119 and AW119 MKII helicopters.

Exact source excerpt. Text positions 12395–12818, end exclusive, in the original decoded publication. SHA-256: fbadcac810dfba5714d544964d7cb20d3051e7e37296136e5e02f3d9d0b7f84a

Unsafe Condition
(b) Unsafe Condition

    This AD defines the unsafe condition as a production deficiency 
in a certain Thomas coupling nut. This condition could result in 
failure of the Thomas coupling, failure of the tail drive shaft, and 
subsequent loss of control of the helicopter.

Exact source excerpt. Text positions 12818–13092, end exclusive, in the original decoded publication. SHA-256: c977c40d22fd5c59ab3c3f376462ad9e862c712b51796f0b961fde1eccde3d38

Effective Date
(c) Effective Date

    This AD is effective October 25, 2013 to all persons except 
those persons to whom it was made immediately effective by Emergency 
AD 2013-20-51, issued on October 3, 2013, which contained the 
requirements of this amendment.

Exact source excerpt. Text positions 13092–13343, end exclusive, in the original decoded publication. SHA-256: a09ea80ab1ddf731343c53847e92840d603158a0d455c41457036ab477de39b6

Compliance
(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

Exact source excerpt. Text positions 13343–13530, end exclusive, in the original decoded publication. SHA-256: 56042b53a75a0db2af067b711f9b82d8091413842e43863752e31aeffdd54a72

Required Actions
(e) Required Actions

    (1) Before further flight, using a borescope or light source and 
mirror, inspect each Thomas coupling nut for a crack. If any Thomas 
coupling nut is cracked, before further flight, replace all the 
Thomas coupling nuts with nuts, P/N NAS1805-4, torqueing each nut to 
5.6-7.9 Nm.
    (2) Within 10 hours time-in-service or 30 days, whichever occurs 
first, replace each Thomas coupling nut, P/N MS21042L4, with a nut, 
P/N NAS1805-4, torqueing each nut to 5.6-7.9 Nm.
    (3) After the effective date of this EAD, do not install a nut, 
P/N MS21042L4, on any Thomas coupling.

Exact source excerpt. Text positions 13530–14135, end exclusive, in the original decoded publication. SHA-256: cca14f4f6731790c555ade41fc3e175da031d08c9fc5b4f3ae65df502c2cc452

Alternative Methods of Compliance (AMOCs)
(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Safety Management Group, FAA, may approve AMOCs 
for this AD. Send your proposal to Gary Roach, Aviation Safety 
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA, 
2601 Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5110; 
email [email protected].
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office, before operating any aircraft 
complying with this AD through an AMOC.

Exact source excerpt. Text positions 14135–14856, end exclusive, in the original decoded publication. SHA-256: af63dcf34584745e20814cf32773249d6955e310b415cfbd3016897737a905e4

Additional Information
(g) Additional Information

    (1) Agusta Alert Bollettino Tecnico (ABT) No. 109K-58, ABT No. 
109-136, ABT No. 109EP-130, ABT No. 109L-066, ABT No. 109S-055, ABT 
No. 109SP-069, and ABT No. 119-061, all dated September 20, 2013, 
which are not incorporated by reference, contain additional 
information about the subject of this AD. For service information 
identified in this AD, contact: Agusta Westland, Customer Support & 
Services, Via Per Tornavento 15, 21019 Somma Lombardo (VA) Italy, 
ATTN: Giovanni Cecchelli; telephone 39-0331-711133; fax 39 0331 
711180; or at http://www.agustawestland.com/technical-bullettins. 
You may review a copy of the service information at the FAA, Office 
of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137.
    (2) The subject of this AD is addressed in European Aviation 
Safety Agency (EASA) Emergency Airworthiness Directive 2013-0225-E, 
effective September 21, 2013. You may view the EASA AD at http://www.regulations.gov in Docket No. FAA-2013-0881.

Exact source excerpt. Text positions 14856–15902, end exclusive, in the original decoded publication. SHA-256: d54ee07b3fa31381feb6c301324b8e6bfc8872b06a58882c46301302aa2f653a

Subject
(h) Subject

    Joint Aircraft Service Component (JASC): 6400 Tail rotor system.

Exact source excerpt. Text positions 15902–15985, end exclusive, in the original decoded publication. SHA-256: b7fcf5a3871a8fb0ebb7ead6a8f87660ae7331a9365c68b445a4332715511b45

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2013-20-51 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 01023729f74a0aea8249d32d1fcdce4d0c1a008ae13019f8c6e54c43bb1f0096. Source manifest: 7a0486a7faf2187ccfc301e54fa58acebc81f83f6b8bca50def7a1e217bd9387.

Official source · 2013-10-25

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 78, Number 207 (Friday, October 25, 2013)]
[Rules and Regulations]
[Pages 63850-63852]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-24937]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0881; Directorate Identifier 2013-SW-056-AD; 
Amendment 39-17628; AD 2013-20-51]
RIN 2120-AA64


Airworthiness Directives; AgustaWestland S.p.A. (Agusta) 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for Agusta 
Model A109A, A109A II, A109C, A109E, A109K2, A109S, AW109SP, A119, and 
AW119 MKII helicopters. The emergency AD was sent previously to all 
known U.S. owners and operators of these helicopters. This AD requires, 
before further flight, inspecting certain Thomas coupling nuts on the 
tail rotor drive shaft line for a crack and replacing all the nuts if 
any nut is cracked. Also this AD requires replacing all affected Thomas 
coupling nuts within 10 hours time-in-service (TIS) or 30 days, 
whichever occurs first. This AD was prompted by two incidents of 
cracking on the nuts that connect the flexible disc coupling (Thomas 
coupling) with the splined adapter on the tail rotor drive shaft. We 
are issuing this AD to correct the unsafe condition on these 
helicopters.

DATES: This AD is effective October 25, 2013 to all persons except 
those persons to whom it was made immediately effective by Emergency AD 
2013-20-51, issued on October 3, 2013, which contained the requirements 
of this amendment.
    We must receive comments on this AD by December 24, 2013.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
    <bullet> Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the Docket Operations Office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the foreign authority's AD, 
the economic evaluation, any comments received, and other information. 
The street address for the Docket Operations Office (phone: 800-647-
5527) is in the ADDRESSES section.
    For service information identified in this AD, contact Agusta 
Westland, Customer Support & Services, Via Per Tornavento 15, 21019 
Somma Lombardo (VA) Italy, ATTN: Giovanni Cecchelli; telephone 39-0331-
711133; fax 39 0331 711180; or at http://www.agustawestland.com/technical-bullettins. You may review the referenced service information 
at the FAA, Office of the Regional Counsel, Southwest Region, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Gary Roach, Aviation Safety Engineer, 
Regulations and Policy Group, Rotorcraft Directorate, FAA, 2601 Meacham 
Blvd., Fort Worth, TX 76137; telephone: (817) 222-5110; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    On October 3, 2013, we issued Emergency AD 2013-20-51, which 
requires, before further flight, inspecting certain Thomas coupling 
nuts on the tail rotor drive shaft line for a crack and replacing all 
the nuts if any nut is cracked. Also the emergency AD requires 
replacing all affected Thomas coupling nuts within 10 hours TIS or 30 
days, whichever occurs first. This emergency AD was sent previously to 
all known U.S. owners and operators of these helicopters. This action 
was prompted by two incidents of cracking on the nuts that connect the 
flexible disc coupling (Thomas coupling) with the splined adapter on 
the tail rotor drive shaft.
    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Union, has issued EASA AD 
No. 2013-

[[Page 63851]]

0225-E, dated September 20, 2013, to correct an unsafe condition for 
certain Agusta Model A109A, A109A II, A109C, A109E, A109K2, A109S, 
AW109SP, A119, and AW119 MKII helicopters. The EASA advises that during 
scheduled inspection on the tail rotor drive shaft line of two in-
service Model AW109SP helicopters, one part-numbered nut that connects 
the Thomas coupling with the splined adapter was cracked. The 
subsequent investigation identified that the reported cracks of the 
nuts are the results of a production deficiency (hydrogen 
embrittlement) at the nut supplier.

Related Service Information

    Agusta has issued the following service information:
    <bullet> Alert Bollettino Tecnico (ABT) No. 109K-58 for all Model 
A109K2 helicopters;
    <bullet> ABT No. 109-136, for all Model A109A, A109A II, and A109C 
helicopters;
    <bullet> ABT No. 109EP-130, for Model A109E helicopters up to and 
including serial number (S/N) 11832, except S/N 11796, from 11808 to 
11810, and from 11812 to 11829;
    <bullet> ABT No. 109L-066 for all Model A109LUH helicopters;
    <bullet> ABT No. 109S-055, for all Model A109S helicopters;
    <bullet> ABT No. 109SP-069, for Model AW109SP helicopters up to 
including S/N 22316, except S/N 22284, 22286, 22307, and 22308; and
    <bullet> ABT No. 119-061 for Model A119 and AW119 MKII helicopters 
up to and including S/N 14811, except S/N 14805 and 14807.
    All the ABTs are dated September 20, 2013, and specify a one-time 
inspection of the Thomas coupling nuts, part number (P/N) MS21042L4. If 
any nut is cracked, the ABTs specify replacing all nuts with nuts, P/N 
NAS1805-4.

FAA's Determination

    These helicopters have been approved by the aviation authority of 
Italy and are approved for operation in the United States. Pursuant to 
our bilateral agreement with Italy, EASA, its technical representative, 
has notified us of the unsafe condition described in their AD. We are 
issuing this AD because we evaluated all information provided by EASA 
and determined the unsafe condition exists and is likely to exist or 
develop on other helicopters of these same type designs.

AD Requirements

    This AD requires, before further flight, visually inspecting each 
Thomas coupling nut, P/N MS2104L4, along the tail rotor drive shaft 
line for a crack. If any nut is cracked, replacing all the nuts with 
nuts, P/N NAS1805-4, is required before further flight. Replacing all 
nuts, P/N MS21042L4, with nuts, P/N NAS1805-4, is required within 10 
hours TIS or 30 days, whichever occurs first. Finally, this AD 
prohibits installing a Thomas coupling nut, P/N MS21042L4, on any tail 
rotor drive shaft line.

Differences Between This AD and the EASA AD

    This AD differs from the EASA AD in that we include all model 
helicopters rather than limiting the applicability to specific serial-
numbered helicopters, and we do not include Model A109LUH helicopters 
as they do not have a U.S. type certificate.

FAA's Justification and Determination of the Effective Date

    Providing an opportunity for public comments prior to adopting 
these AD requirements would delay implementing the safety actions 
needed to correct this known unsafe condition. Therefore, we find that 
the risk to the flying public justifies waiving notice and comment 
prior to adoption of this rule because inspecting for and replacing a 
cracked nut must be done before further flight, and replacing all nuts 
is required within 10 hours TIS or 30 days, whichever occurs first, 
which is a very short time period based on the average flight-hour 
utilization rate of these helicopters.
    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we determined that notice and opportunity for 
prior public comment are impracticable and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the Docket Number FAA-2013-0881 and 
Directorate Identifier 2013-SW-056-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Costs of Compliance

    We estimate that this AD will affect 222 helicopters of U.S. 
Registry. We estimate the following costs to comply with this AD. Labor 
costs are estimated at $85 per hour. We estimate 2 work hours to 
inspect each nut and 16 work hours to replace all nuts at a cost of 
$1,530 per helicopter and a total fleet cost of $339,600.
    According to the manufacturer, the costs of this AD may be covered 
under warranty, thereby reducing the cost to affected individuals. We 
do not control warranty coverage for affected individuals. As a result, 
we have included all costs in our cost estimate.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on helicopters identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979);
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction; and

[[Page 63852]]

    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared an economic evaluation of the estimated costs to comply 
with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2013-20-51 Agusta S.p.A: Amendment 39-17628; Docket No. FAA-2013-
0881; Directorate Identifier 2013-SW-056-AD.

(a) Applicability

    This AD applies to the following Agusta S.p.A. (Type certificate 
currently held by AgustaWestland S.p.A) (Agusta) helicopters, with a 
tail rotor drive shaft flexible disc coupling (Thomas coupling) nut, 
part number (P/N) MS21042L4, certificated in any category:
    (i) Model A109A, A109A II, A109C, A109E, A109S, A109K2, AW109SP 
helicopters; and
    (ii) Model A119 and AW119 MKII helicopters.

(b) Unsafe Condition

    This AD defines the unsafe condition as a production deficiency 
in a certain Thomas coupling nut. This condition could result in 
failure of the Thomas coupling, failure of the tail drive shaft, and 
subsequent loss of control of the helicopter.

(c) Effective Date

    This AD is effective October 25, 2013 to all persons except 
those persons to whom it was made immediately effective by Emergency 
AD 2013-20-51, issued on October 3, 2013, which contained the 
requirements of this amendment.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Before further flight, using a borescope or light source and 
mirror, inspect each Thomas coupling nut for a crack. If any Thomas 
coupling nut is cracked, before further flight, replace all the 
Thomas coupling nuts with nuts, P/N NAS1805-4, torqueing each nut to 
5.6-7.9 Nm.
    (2) Within 10 hours time-in-service or 30 days, whichever occurs 
first, replace each Thomas coupling nut, P/N MS21042L4, with a nut, 
P/N NAS1805-4, torqueing each nut to 5.6-7.9 Nm.
    (3) After the effective date of this EAD, do not install a nut, 
P/N MS21042L4, on any Thomas coupling.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Safety Management Group, FAA, may approve AMOCs 
for this AD. Send your proposal to Gary Roach, Aviation Safety 
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA, 
2601 Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5110; 
email [email protected].
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office, before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    (1) Agusta Alert Bollettino Tecnico (ABT) No. 109K-58, ABT No. 
109-136, ABT No. 109EP-130, ABT No. 109L-066, ABT No. 109S-055, ABT 
No. 109SP-069, and ABT No. 119-061, all dated September 20, 2013, 
which are not incorporated by reference, contain additional 
information about the subject of this AD. For service information 
identified in this AD, contact: Agusta Westland, Customer Support & 
Services, Via Per Tornavento 15, 21019 Somma Lombardo (VA) Italy, 
ATTN: Giovanni Cecchelli; telephone 39-0331-711133; fax 39 0331 
711180; or at http://www.agustawestland.com/technical-bullettins. 
You may review a copy of the service information at the FAA, Office 
of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137.
    (2) The subject of this AD is addressed in European Aviation 
Safety Agency (EASA) Emergency Airworthiness Directive 2013-0225-E, 
effective September 21, 2013. You may view the EASA AD at http://www.regulations.gov in Docket No. FAA-2013-0881.

(h) Subject

    Joint Aircraft Service Component (JASC): 6400 Tail rotor system.

    Issued in Fort Worth, Texas, on October 16, 2013.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2013-24937 Filed 10-24-13; 8:45 am]
BILLING CODE 4910-13-P


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